Weighing food

In the US, the nutrition information on the label is for the "as packaged" or raw weight unless the label specifies otherwise. So if you want to use the nutrition label on the package then that's how you'll want to weigh it.

The nutrition database here at MFP has information for both the cooked and raw weight, so if you'd rather weigh it after cooking then find an appropriate and accurate entry to use, preferably one that matches your cooking style (ie you wouldn't want to use a "grilled" entry if you boiled it, etc).